276 The Utility of Intravascular Ultrasound in Venous Sinus Stenting

INTRODUCTION: Venous sinus stenting (VSS) is an effective treatment for pulsatile tinnitus (PT) and idiopathic intracranial hypertension (IIH). Patients are typically selected for intervention based on a combination of stenosis measurements on catheter angiography, which carries some degree of subjectivity, and awake intravascular manometry-based pressure gradients. Intravascular ultrasound (IVUS) is a uniquely advantageous tool in this setting: By capturing the luminal area of the irregular venous sinuses, IVUS provides objective stenosis measurements, which may be more reliable for VSS patient selection. METHODS: Retrospective analysis of all patients undergoing venography with IVUS for assessment of venous sinus stenosis over an eight-month period. Angiographic and IVUS measurements of stenosis were compared to manometry pressure gradients. Two independent interventionalists measured angiographic stenosis; the average measurement was used for analysis. RESULTS: A total of 31 patients were included with either IIH (41.9%) or PT (58.1%). The average percent maximal venous sinus stenosis measured by conventional angiography was 51.2% and by IVUS was 65.2%. The interrater correlation of angiographic measurement of stenosis was relatively poor (r2=0.19, p=0.015*). IVUS stenosis measurements correlated with manometry gradients significantly better than angiographic measurements (Pearson’s r=0.78 vs 0.46, p=0.044*). IVUS stenosis of at least 53.2% predicted a manometry gradient =8, our clinical cutoff for stenting, with 100% sensitivity and 66.7% specificity. No device-related adverse events were observed. CONCLUSIONS: IVUS is a safe, reliable, and effective method for assessing venous sinus stenosis, outperforming conventional angiography in accurately measuring stenosis correlating to high intravenous pressure gradients. With its potential to establish a threshold percent stenosis responsive to VSS if investigated in a larger cohort, IVUS represents a promising tool for refining treatment criteria. Our findings advocate for the integration of IVUS into future VSS protocols to optimize patient selection.